Supplements to Avoid
As indicated in previous chapters, high cortisol levels are associated with being overweight, and yet at the same time cortisol levels are elevated by dieting and by cognitive dietary restraint (a fancy term for thinking about dieting). It is no wonder, then, that people who are under chronic or repeated stress tend to struggle with their weight, their appetite, and their energy levels—all of which are impacted by the elevated cortisol levels associated with their stress. It would seem to be a virtual miracle for a dietary supplement to come along with claims of increasing weight loss, suppressing appetite, and boosting energy levels. In fact, this supplement would almost seem to be tailor-made for people under stress, because it addresses three of the key factors that lead them down the path to weight gain.
The "miracle" supplements described above fall into a category of herbal stimulants that function as sympathomimetics—meaning they mimic some of the effects of the body's own sympathetic (stimulant) hormones such as epinephrine and norepinephrine, either by increasing the secretion of those hormones or by reducing their breakdown. Among the most popular herbals in this category are Ephedra sinensis (ma huang), Citrus aurantium (synephrine), Coleus forskohlii (forskolin), Paullinia cupana (guarana/caffeine), and Pausinystalia yohimbe (yohimbine)—but many other plant species contain related stimulant compounds. Each of these herbs acts as a general stimulant on many parts of the body simultaneously, including the lungs (where they can open bronchioles to make breathing easier), the heart and blood vessels (where they increase heart rate and constrict arteries to increase blood pressure), and even the adrenal glands (where they stimulate the secretion of epinephrine and cortisol). Because of these wide-ranging actions in many tissues, the herbal stimulants are also frequently associated with a number of adverse side effects such as headaches, insomnia, elevated blood pressure, irritability, and heart palpitations. But perhaps the side effect that provokes the most concern is the large increase in cortisol levels caused by these substances.
The widespread popularity of the herbal stimulants—most notably ephedra—is due largely to the fact that they work (at least in the short-term). Ephedra and related supplements are well known to kill appetite and increase energy levels, so you either exercise more or you fidget more, but either way you burn some extra calories. This means that over the course of a month or two, the herbal stimulant products will help a person drop a few more pounds than he otherwise would have been able to do on his own. The downside, however, is the fact that while the short-term effects of these compounds are beneficial for weight loss (by reducing appetite and increasing caloric expenditure), the longer-term increase in cortisol levels is detrimental for weight-loss efforts. Why? Because, as outlined previously, the increase in cortisol levels will increase hunger, slow down fat metabolism, eat away at muscles and bones, sap energy, wreck mood, and generally thwart attempts to maintain a healthy body weight.
So here we have a class of weight-loss supplements that provides some actual benefits when used for a few weeks, but then turns on the user to cause a series of metabolic changes in the body that promote weight gain over several months. If that news isn't already bad enough, it also appears that the tendency of ephedra and related compounds to cause weight gain over a longer period of time is even stronger when the user is experiencing an additional stressor (and dieting is a stressor). Researchers from Lausanne University, in Switzerland, found that as little as two days of ephedra consumption, at 40 milligrams (mg) per day, reduced glucose uptake and oxidation by 25 percent. When subjects were under additional stress, the fall in glucose uptake and oxidation exceeded 50 percent! This means ephedra supplements inhibit the body's ability to use glucose as an energy source, so blood-sugar levels climb, fat metabolism shuts off, and hunger comes raging back. Similar findings have been noted for forskolin (the active ingredient in Coleus forskohlii), yohimbine (the active ingredient in Pausinystalia yohimbe), and caffeine (the active ingredient in yerba mate, Kola nut, and Paullinia cupana, also known as guarana). For example, approximately 200 mg of caffeine (about the amount contained in two cups of coffee and in a single dose of many weight-loss supplements) will increase blood levels of cortisol by 30 percent within one hour. Researchers from the University of Oklahoma have shown that caffeine not only causes elevations in cortisol levels, but also that the combination of caffeine intake plus increased stress causes an even bigger jump in cortisol exposure (and when do we drink the most coffee? Yep, when we're under stress). The Oklahoma scientists found that both men and women respond to caffeine plus stress with much higher cortisol levels—and that repeated doses of caffeine continue to increase cortisol levels throughout the day.
What we see in the longer-term studies of herbal stimulants is a persistent elevation in plasma cortisol levels caused by a stresslike neuroendocrine response to stimulation of the brain and the adrenal glands. In animal studies, this type of nervous-system stimulation leads not only to elevated cortisol levels, but also to reductions in levels of growth hormone and thyroid-stimulating hormone, both of which are involved in keeping us lean.
So what to do? The most prudent approach would be to completely avoid these herbal stimulants in favor of a more balanced approach to promoting weight loss, such as eating several small meals spaced throughout the day, consuming a balanced intake of protein/carbs/fat/fiber, and getting regular aerobic exercise (plus resistance training). That said, millions of people are likely to keep using products that have herbal stimulants in them. Despite the long-term risk to overall health and the sabotage such supplements can inflict on a person's weight-maintenance efforts, the quick-fix promise of dropping a few extra pounds in a few weeks is simply too much for many people to resist. If you do decide to use any of these herbal stimulants, please do so with extreme caution—and try to curb your use of them after one month. At the very least, the cortisol-raising effects of the herbal stimulants should be counteracted by combining their use with one of the cortisol-lowering herbs outlined later in this chapter. It is unlikely that the cortisol-controlling supplements will counteract either the appetite-control or the thermogenic/fat-burning effects of the herbal stimulants, but they will certainly lessen the adverse side effects of elevated cortisol. The rest of this section provides brief summaries of each of the most popular herbal stimulants used in weight-loss supplements.
Ma huang is a Chinese herb that is also referred to as Chinese ephedra (Ephedra sinensis) and herbal ephedrine. The active compounds—ephedra or ephedrine alkaloids—are also found in other herbals, such as Mormon tea and Sida cordifolia, and may be referred to by common names such as desert tea, Mexican tea, sea grape, and many others. Overall, about forty species of plants contain versions of ephedra.
Ma huang and its various herbal cousins function as sympathomimetics, the effects of which are described earlier in this chapter. Ephedrine is considered a nonselective sympathomimetic, which means that it acts as a general stimulant on many parts of the body simultaneously (lungs, heart, blood vessels, adrenal glands, and others). Therefore, it can give users a boost or pickup similar to what they might feel after a cup or two of strong coffee. By mimicking the effects of epinephrine, ephedra can increase the output of blood from the heart, enhance muscle contractility, raise blood-sugar levels, and open bronchial pathways for easier breathing. In many cases, ephedra can result in a temporary suppression of appetite, which may help efforts aimed at dietary restriction and weight loss.
The research findings concerning the effects of ma huang and other ephedra-containing products are equivocal; some studies show absolutely no beneficial effect, some studies show a modest increase in weight loss, and still other studies become unreliable, due tosuffer from high numbers of subjects dropping out due to unpleasant side effects. Because ephedrine is a stimulant, it is logical that either a single dose or chronic repeated use would elevate metabolic rate somewhat (meaning the user would burn more calories at rest and during exercise). Various studies of overweight men and women have shown that the combination of ephedrine (20–40 mg) and caffeine (200–400 mg) produces a slight increase in resting metabolism.
The Food and Drug Administration (FDA) has received more than a thousand reports of adverse side effects from consumers using supplements containing ephedrine alkaloids. Complaints have ranged from nervous-system and cardiovascular-system effects, such as elevated blood pressure and heart palpitations, to insomnia, irritability, headaches, and more serious adverse effects, such as seizures, stroke, heart attack, and even death (about fifteen to twenty thus far). Most of these adverse events occurred in otherwise healthy, young to middle-aged adults who were using the products for weight control or increased energy.
Health Warning for Ephedra-Containing Dietary Supplements
Virtually all dietary supplements that contain ephedra alkaloids also carry a strong warning on their label. It reads something like the following: Women who are pregnant or nursing should avoid using ephedra-containing products. Keep out of reach of children. Avoid using ephedrine-containing products if you have high blood pressure, heart or thyroid disease, diabetes, difficulty in urination due to prostate enlargement, or if taking monoamine oxidase (MAO) inhibitors or any other prescription drug. Reduce or discontinue use if nervousness, tremor, irritability, rapid heartbeat, sleeplessness, loss of appetite, or nausea occurs.
Across the range of studies that have been conducted on products containing ephedra for weight loss, the total amount of ephedrine ingested per day has ranged from 60 to 75 mg of ephedrine alone (usually in three doses of 20–25 mg each) to 20–40 mg of ephedrine combined with 200–400 mg of caffeine. It is important to note, however, that these dosage recommendations should be considered in light of recent studies showing that the levels of ephedra alkaloids can vary by as much as 1,000 percent from one dietary supplement to another.
The purified versions of ephedra (ephedrine and pseudoephedrine) found in many over-the-counter cold medicines have the very same effect on cortisol levels (raising them). However, in contrast to ephedra-based weight-loss supplements, which might be used for many weeks at a time (and thus lead to chronically high cortisol levels), typical cold remedies are used for no more than a few days in a row and thus would cause only a temporary rise in cortisol levels. Should you decide to use ephedra-containing products, it is important to understand that while the short-term effects (suppressed appetite and slight increase in caloric expenditure) might give your weight-loss efforts a boost, the longer-term effects (chronically elevated cortisol levels) will sabotage your ability to maintain that weight loss. Therefore, ephedra supplements should be used for no more than six to twelve weeks, and even then, for optimal effect, they should be balanced with supplemennt that help to control cortisol levels.
Guarana (Paullinia cupana) comes from the seeds of a Brazilian plant. Traditional uses of guarana by natives of the Amazonian rain forest include adding crushed seeds of the plant to foods and beverages to increase alertness and reduce fatigue. As a dietary supplement, it's no wonder guarana is an effective energy booster; it contains approximately twice the caffeine found in coffee beans. Guarana seeds are about 3–4 percent caffeine, compared to the 1–2 percent in coffee beans. Concentrated guarana extracts, however, can contain as much as 40–50 percent caffeine, with popular supplements delivering 50–200 mg of caffeine per day, about the same amount found in one or two cups of strong coffee. Guarana is generally considered to be as safe for healthy people as caffeine. As with any caffeine-containing substance, guarana extracts can lead to insomnia, nervousness, anxiety, headaches, high blood pressure, and heart palpitations.
The theory behind how guarana works is relatively straightforward. The major active constituents are caffeine (sometimes called guaranine to make the user think it's different in some way) and similar alkaloids such as theobromine and theophylline, which are also found in coffee and tea. Each of these compounds has well-known effects as nervous-system stimulants. As such, they may also bear some effect on increasing metabolic rate, suppressing appetite, and enhancing both physical and mental performance.
Most of the scientific evidence on caffeine as a general stimulant and an aid to exercise performance shows convincingly that caffeine is effective. As a weight-loss aid, however, although high doses of caffeine may somewhat suppress appetite, on its own it does not seem to be a very effective supplement for increasing caloric expenditure (thermogenesis). However, when combined with other stimulant-type supplements, such as ma huang (ephedra), it appears that caffeine can extend the duration of ephedra's action in suppressing appetite and increasing caloric expenditure; it is unknown whether caffeine may also increase the risk of adverse side effects.
Synephrine is the main active compound found in the fruit of a plant called Citrus aurantium. The fruit is also known as zhi shi in traditional Chinese medicine, and as green orange, sour orange, and bitter orange in other parts of the world. Synephrine is chemically very similar to the ephedrine found in a number of weight-loss and energy supplements that contain ma huang. But synephrine differs from ephedrine in that synephrine is considered a semiselective sympathomimetic (because it targets some tissues, such as fat, more than it targets others, such as the heart) versus a nonselective sympathomimetic (like ephedra, which targets many tissues equally and thus often causes side effects). For example, although some high-dose ephedra-containing supplements have been associated with certain cardiovascular side effects such as elevated blood pressure and heart palpitations, researchers at Mercer University, in Atlanta, have shown that Citrus aurantium extract has no effect on hemodynamics such as heart rate and blood pressure because it targets fat tissue rather than heart tissue.
Because synephrine, like caffeine and ephedrine, is a mild stimulant, similar in some ways to caffeine and ephedrine, it is also thought to have similar effects in terms of providing an energy boost, suppressing appetite, and increasing metabolic rate and caloric expenditure. In traditional Chinese medicine, zhi shi is used to help stimulate qi (pronounced chee, and defined as the body's vital energy or life force), but in order to maximize the metabolic benefits of these extracts, total synephrine intake should probably be kept to a range of 2–10 mg per day.
One study in dogs suggests that synephrine and octopamine found in Citrus aurantium extracts can increase metabolic rate in a specific type of fat tissue known as brown adipose tissue (BAT). This effect would be expected to increase fat loss in humans, except for one small detail: Adult humans don’t have any brown adipose tissue to speak of. Despite this fact, this claim still stands as one of the most overhyped promises on the weight-loss scene. Since being introduced to the market more than 10 years ago, synephrine-containing supplements have existed solely because of some interesting theories on how they might work to increase metabolic rate and promote significant weight loss. At this writing, there is still a glaring lack of credible research showing any weight loss effects of synephrine supplements in humans. In fact, most of the available human clinical trials on synephrine-based supplements sugegst that they are not particularly effective for promoting weight loss.
Yohimbe (Pausinystalia yohimbe) comes from the bark of an African tree; the active compound, an alkaloid called yohimbine, can also be found in high amounts in the South American herb quebracho (Aspidosperma quebracho-blanco). It has traditionally been used as a stimulant and aphrodisiac in West Africa and South America. In the United States, yohimbe and quebracho are most often promoted in dietary supplements for treating impotence, stimulating male sexual performance (often marketed as "herbal Viagra"), and enhancing athletic performance (as an alternative to anabolic steroids). More recently, however, yohimbe and quebracho have also been showing up in dietary supplements focused toward promoting fat loss and muscle gain at the same time.
A purified extract from yohimbe bark yields yohimbine, which is similar in chemical structure to caffeine and ephedra; it is regulated as a prescription medication for treating erectile dysfunction in males. Yohimbine functions as a monoamine oxidase (MAO) inhibitor to increase levels of the neurotransmitter norepinephrine, but it also acts as a stimulator of the central nervous system, where it interacts with specific receptors (alpha-2 adrenergic receptors) and may increase energy levels and promote fat oxidation.
Although yohimbe is frequently promoted as a natural way to increase testosterone levels for muscle building, strength enhancement, and fat loss, there is no solid scientific proof that yohimbe is either anabolic or thermogenic. Results from a few small trials show that purified synthetic yohimbine can increase blood flow to the genitals, an effect that may occur in both men and women. As such, yohimbe bark, which contains small amounts of natural yohimbine, may be effective in alleviating some mild forms of both "psychological" and "physical" impotence. However, in the few studies conducted on the purified form of yohimbine, only about 30 percent of subjects reported beneficial effects in terms of erectile function and sexual performance.
As the number of yohimbe products on the retail market increases, concerns about their safety are raised because of the reported toxicity of yohimbine. Reported side effects from yohimbe use include minor complaints such as headaches, anxiety, and tension, as well as more serious adverse events, including high blood pressure, elevated heart rate, heart palpitations, and hallucinations. People with high blood pressure and kidney disease should avoid supplements containing yohimbe, as should women who are, or who could become, pregnant (due to a potential risk of miscarriage). Also, caution should be used when taking yohimbe in combination with certain foods containing tyramine (such as red wine, liver, and cheese) as well as with nasal decongestants or diet aids containing ephedrine or phenylpropanolamine, which could lead to dangerous blood-pressure fluctuations.
Coleus (Coleus forskohlii) is part of the mint family of plants and has long been used in India, Thailand, and parts of Southeast Asia as both a spice and an Ayurvedic medicine for treating heart ailments and stomach cramps. The roots of the plant are a natural source of forskolin, a compound that can increase cellular levels of cyclic adenosine monophosphate (cAMP), an effect that is theorized to influence many aspects of metabolism. The primary use of coleus extracts in modern dietary supplements is for a purported effect in promoting weight loss and stimulating muscle growth.
The theory behind Coleus forskohlii as a dietary supplement is that its content of forskolin can be used to stimulate adenylate cyclase activity, which will increase cAMP levels in the fat cell, in turn activating another enzyme (hormone-sensitive lipase) to start breaking down fat stores. The problem with this theory is that cAMP regulates the activity of hundreds of enzymes in each cell—and those enzymes can be quite different from cell to cell. For example, we know that in cell cultures (test-tube studies), adding forskolin to fat cells will increase cAMP levels and stimulate lipolysis (breakdown of stored triglycerides into free fatty acids). Add that same forskolin to muscle cells, however, and the primary effect is to stimulate glycogenolysis (breakdown of stored glycogen into free glucose units). Add forskolin to liver cells and you get a stimulation of gluconeogenesis (synthesis of blood glucose from amino acid precursors).
Most of the work conducted on the actions of forskolin has been confined to test tubes. There are no published trials showing that the supplement promotes either weight loss or increased lean body mass or any other health benefit in humans, though health food–industry publications frequently tout a small, poorly conducted trial of six overweight women in whom 500 mg of coleus extract per day for eight weeks caused a loss of body fat and an increase in muscle mass. These data are completely useless to us, as there were no blinding of subjects and no placebo control group, so there is no way to determine whether the weight loss was due to the supplement (which is highly unlikely) or to some other factor, such as a change in diet or exercise patterns (far more likely).
The typical dosage recommendations for coleus extracts are in the range of 100–300 mg per day (10–20 percent forskolin), which appears to be more than enough to induce a significant rise in blood levels of cortisol.
Summary: Supplements to Avoid
I hope the preceding information helps to put some of the "miracle" weight-loss claims for herbal stimulants into proper perspective. Far from being a stand-alone solution for weight maintenance, these supplements—while they offer the benefits of appetite control, enhanced energy levels, and increased caloric expenditure—absolutely must be used within the proper dosage range (and, even better, should be used in conjunction with at least one cortisol controller). At excessive doses, users risk adverse side effects, long-term elevations in cortisol levels, and the associated metabolic changes that can sabotage weight-loss efforts.
But there is good news. The rest of this chapter profiles some of the supplements that are most effective for controlling stress, balancing cortisol levels, and dealing with many of the associated metabolic changes.